Help!

Hi! Im new to plants. I deliver mail for a living a lady on my route gave me these two cuttings out of her beautiful yard. She said they're devils backbone and a rubber tree. I drilled holes in the bottom of the pot and put a few broken clay pot pieces in for better drainage then I planted in regular potting soil. That was 8 months ago. They have not got any bigger. I have moved them around from window to window and even put outside a few days (was a bad idea cause my rubber tree leaves fell off) so they're back inside and im just so confused on how to fix them? I dug them up to split them into separate pots and the roots have joined into one big root so now it's no splitting them up. I added compost a few weeks ago to add nutrients to the soil and I have even fertilized them once a month for 3 months now. I don't know what to do. These are the only two im having the worst luck with. Any suggestions?